title: Production of sophorolipids from non-edible jatropha oil by Stamerella bombicola NBRC 10243 and evaluation of their interfacial properties.
abstract: To facilitate the development of bio-based chemicals from renewable and inexpensive natural resources, we sought to produce biosurfactants using non-edible jatropha oil. Twenty yeasts known to produce biosurfactants were tested in this study, and Stamerella bombicola NBRC 10243 was found to use jatropha oil efficiently to produce sophorolipids (SLs) as a mixture of lactone-form SL (L-SL) and acid-form SL (A-SL). Under culture conditions using rice bran as the source of organic nutrients, the yield of SLs reached 122.6 g/L in 5-L jar fermentors after 9 d in culture. HPLC analysis of the culture medium showed that the levels of phorbol esters (PEs), major toxic components of the oil, decreased markedly with an increase in culture time, suggesting that the yeast degrades PEs. Although the SLs obtained by solvent extraction of the culture medium contained a small amount of PEs, the sodium salt of A-SL (A-SL-Na) obtained by alkaline treatment (5N NaOH, 80°C) showed no PE peaks upon HPLC analysis. A-SL-Na had excellent surface activity with low CMC (9.0×10⁻⁴ M) and γ(CMC) (29.6 mN/m), which are lower than that of sodium dodecyl sulfate (SDS). The solubilizing ability of A-SL-Na toward for octanoic acid ([octanoic acid]/[A-SL-Na]) was found to be 2.0, which is half that of SDS. Our findings should help improve SL production from non-edible feedstock and broaden the use of promising bio-based surfactants.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST).
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawamura
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Shun
authors.initials: S
authors.lastname: Sato
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yamagata
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.forename: Koji
authors.initials: K
authors.lastname: Wada
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D053898:Biosynthetic Pathways; D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques; D006017:Glycolipids / Q000096:biosynthesis* / Q000737:chemistry; D031286:Jatropha; D008828:Microbiological Techniques; D008968:Molecular Conformation; D010703:Phorbol Esters / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism*; D004718:Saccharomycetales / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*; D013997:Time Factors; D015003:Yeasts / Q000378:metabolism
chemical_list: D003470:Culture Media; D006017:Glycolipids; D010703:Phorbol Esters; D010938:Plant Oils; D013501:Surface-Active Agents